Change Boots/Seals when doing Spark Plugs?

[chefduane]

I am going to change my sparkplugs pretty soon on my '11 3.5L (75k miles) and am also going to do upper/lower intake manifold gaskets while I'm at it. My experience with my '98 Explorer was that eventually they dry out and no longer expand as needed so I'm going to do them on the Edge while I have everything disassembled - very cheap preventative maintenance anyway.

 

My question is this - should I go ahead and do the plug boots and seals while I'm at it? I have read that sometimes the seal can lodge itself in the plug recess and be difficult to remove. It can require destroying it to get it out with a coat hanger or a roach clip...err..uh.. hemostat.

 

Rock Auto has the Ford SP520 OEM plug for about $20 a set, the gaskets for $35 for uppers and lowers, but a complete boot and seal set (6) is about $60. I thinking I may go for it simply for the insurance of possibly damaging one or more during extraction. And even if I don't I'll have a new set of boots/seals in there.

 

I'm just interested in some feedback from the group. Thanks!

[autom8r]

chef:

 

At 75k your gaskets are still pliable. They're made of silicone, probably the same stuff that your silicone oven mitts are made from. If you still have the Edge at 150k, change them at that time. The only reason that I can think of that would require you to change them is if somehow you damaged them in the removal process. This would be difficult to do.

 

Leave the lower intake manifold gasket alone. A spark plug change out does not require you to remove the entire manifold. Unless of course, you feel the compulsion to do so, that's your prerogative.

 

The plug boots and seals you speak of is really a valve cover gasket issue. A COP is a molded rubber assembly. There are no "boots" as in a typical spark plug boot. The COP is housed in a metal sleeve which creates a knife edge seal with the "boot" (I guess?) of the COP. When the COP is pressed onto the plug, the COP seals itself with the knife edge on the valve cover casting. Outside this sleeve, there is an o-ring that the valve cover interfaces with. It is a clever (COP in sleeve) design that I wish BMW would steal and adopt into their VCG design (since BMW VCGs get crispy and fail frequently). Since the sleeve is continuous, oil can never seep into and fill the sleeve causing the plug to misfire.

 

COP, note inside surface of the top. This is the contact point for the valve cover casting and knife edge seal.

 

 

Top view, all round simple gaskets. note the protrusion in the casting for the knife edge seals for the COPs.

 

 

 

Bottom view (inside, not o-ring seals for spark plug sleeves); Note that even the perimeter gasket is an o-ring.

 

In order to remove and replace the sleeve seals, the valve covers must be removed. A daunting task, especially in the back against the firewall.

 

The tricky part is to release the little red clips without breaking them, after that, twist the COP while pulling on it. It should pop right off. You'll be surprised that there is very little dirt/debris there is in the spark plug sleeve. Use a can of compressed air to blast out anything that's in there before removing the plug from the sleeve. Practice on the front set first.

 

My advice, ditch the boots and seals, whatever those are. Unless there is a leak from the valve cover.

 

Happy trails.

[omar302]

This is the COP Boot. I'd also be interested weather changing it is a good measure or not.

 

[chefduane]

Autom8tr, thanks for the info! Yes, I was/am most concerned about the 'O' seal at the top of the COP assembly. As I mentioned, it was noted that they sometimes can get damaged pulling out the COP. Rock Auto does not just sell the seal part but sells the seal and the lower boot portion of the COP assy as a set only. I am not sure if I am using the correct terminology but I trust you understand what I am talking about. I guess I will just be very careful about removing the whole COP.

 

re: manifold gaskets - my concern is twofold; 1) I have seen a few video's that recommend removing the manifold to get at the rear bank of plugs. I figured as long as I had it off I would change out the gaskets as they are relatively cheap, and 2) I don't want to pull off the manifold again to do a separate gasket change even if it is a while off.

 

I will not be removing the valve cover so there will be no need for a valve cover gasket.

 

Thanks again for the feedback.

Edited May 2, 2017 by chefduane

[WWWPerfA_ZN0W]

I put new COPs on mine, so I can't really comment on booting the boot. BUT even at 90K, I did lose a bank 1 boot to the spark plug Glad I had already decided to put in new COPs, not wanting to face PCM failure.

[autom8r]

chef:

 

You'll need to remove the upper manifold to get at the rear COPs and plugs. You'll be partially blind removing the rear COPs and plugs. Practice removing the coil wires on the front group of COPs that way you wont break the stupid little red clips. The red clips slide in the direction of the clip, so don't lift or pry. After the red clip is slid out, press the black spring clip and the plug will release from the COP. Remove the retainer bolts after the wires have been disconnected.

 

It's true, the COP is two pieces so technically there is a boot. I kept my old COPs and looked at them last night, pulled the boot (thanks Omar) off the COP and I think it's basically just an adapter. There's a spring in it that presses against the top of the plug and another spring at the top of it that presses against a flat contact at the bottom of the COP. A new set of COPs comes complete with a set of boots as an assembly, ergo my interpretation that there were no boots in the traditional sense. I surmise that some valve covers may be deeper (maybe?) requiring the boot to be longer? That would probably be a different part number. Examine the boots though, if there are cracks, etc. discard and replace.

 

My original COPs lasted 150k miles (no surface defects observed on the boots) and were still working when I swapped them for the ACCEL 140061 coils (and boots). Cosmetically, the yellow dresses up the engine bay. Technically, I don't think that they're any better than stock.

 

With 193k on the odometer, I've never touched the lower manifold gasket.

 

macbwt chime in if you want.

 

Over and out.

[macbwt]

I will say I am currently running the original Upper plenum gasket on my 2011 at nearly 200K miles. I do plan on changing the Upper plenum gasket this time, but if I did not I would not necessarily worry about it.

 

I have never changed the valve cover gaskets and do not plan on it until there is a leak and I have never had a valve cover gasket leak on any Edge.

 

If you are going to change the valve cover gasket you may as well update the valve cover on bank 2 to the new modified valve cover to reduce the oil issues associated with the old design.

 

At 200K I am still using the OEM coils. I plan on and have new coils for the Edge to change out this time as the resistance is increasing in the OLD coils so it is about time to change them.

 

I never changed the boots on the coils in a previous spark plug change but it never hurts to have the boots handy just in case (at least two) Never had a boot glue it's self to the plugs but I use dielectric grease on them.